RockyL
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Joined: 09/23/2009
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I have searched the net but have been unable to find relaible (factory)towing information for my 1975 1/2 ton, Chevy 4 x 4 truck. The truck has a 350 4 bbl., auto trans and 373 gears. I would appreciate any info you could provide.
tkx
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Caddywhompus
Southeast WI
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Joined: 06/27/2001
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Why, are you worried about voiding your warranty?!
Seriously, on a truck that old I would say you can tow what you feel comfortable with, as long as the right safety equipment is in place.
A realistic number to stay under would probably be about 6000 pounds, but with a carburetor on top of your small block you are looking at likely a lot less power than any of the later generation fuel-injected versions of your motor. Plus, you'll have issues climbing into the mountains as a carb can't adjust mixture like a computer can, so expect to lose a LOT of power in the Rockies, and put a LOT of soot on the front of the camper.
'04 Ford Freestar (Primary tow vehicle)
'05 Subaru Forester (Backup tow vehicle)
'65 Bethany popup (best popups ever made!)
Looking for a tow vehicle
Minivan towing
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SoCalDesertRider
SanDiego, CA, USA
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The 4 ratings that will be your guides, which can all be found on the vehicle without searching on the internet, are the GVWR, rear axle weight rating, rear tire load capacity and hitch rating. GVWR and rear axle weight rating are right on the VIN info plate on the door jam. Tire load capacity info is right on the tire sidewalls. Hitch capacity is on the hitch, unless the sticker is worn off or missing.
Take the truck to a truck scale, which can be found at most landfills, rock quarries, feed supplys and border checkpoints. Weigh the whole truck, then weigh just the rear axle.
Take the GVWR and subtract the whole truck scale weight. The difference is the Payload capacity of the truck. The trailer's hitch weight should not exceed the truck's payload capacity.
Take the rear axle weight rating and subtract the rear axle scale weight. The difference is how much load capacity is available on the rear axle.
Take the rear tire load capacities and multiply by 2. Subtract the rear axle scale weight from the sum of the tire load capacities. The difference is how much free tire load capacity is available.
Make note of the hitch ratings. The hitch will have 4 ratings. One pair of ratings are for total trailer weight and tongue weight in weight carrying application and the second, higher set of ratings is for weight distributing applications. Total trailer weight must be less than the max trailer weight rating.
Trailer tongue weight must be less than all of the above numbers, gross vehicle payload, rear axle payload, available tire load capacity and hitch tongue weight rating.
Within those ratings, the max weight the truck can tow depends on how it performs with the load.
92F350 CrewCab 4x4 351/C6
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mowermech
Billings, MT
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I had quite a few mid-70's trucks, and I don't remember any door jamb stickers like the trucks of today have. But back then I wasn't looking for them, either.
Does anybody know when those stickers became mandatory?
I'm with the "If it feels good, do it" group on this one. GVWR has at best a tenuous relationship to GCWR.
You could always go online and try to find an Owner's Manual for your antique truck. The GCWR MIGHT be listed in there.
Good luck.
CM1, USN (RET)
'94 Dodge 3500 4X2 CTD, 5 speed, 4.10 LS diff., Jacobs Rambrake, 274,000 Miles
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Daily driver: '08 Subaru Outback
Towed: '06 Jeep Rubicon Unlimited/Load Trail 16' flatbed
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SoCalDesertRider
SanDiego, CA, USA
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My '78 Dodge D150 had the door sticker. It was on the door rather than the door jamb. I had a driver door from a D250 on the truck with a different vin number. The DMV didn't like the 2 different VINs on the same truck when they did their inspection!
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JIMNLIN
Big Cabin, OK
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Certification tag for GVWR/GAWR became mandatory in '69 per part 567.4.
Part 567: Certification
Scope and Purpose:
"This part specifies the content and location of, and other requirements for the certification label or tag to be affixed to motor vehicles and motor vehicle equipment manufactured after 8-31-69. This certificate will provide the consumer with information to assist him or her in determining which of the Federal Motor Vehicle Safety Standards are applicable to the vehicle or equipment, and its date of manufacture."
The truck will haul its rated FAWR/RAWR per its door tag. The semi float axles for 1500 trucks of that era were small as were TT's compared to the latest models today.
"good judgment comes from experience, and a lot of that comes from bad judgment" Will Rogers
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BenK
SF BayArea
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I didn't look for weight labels till borrowed dads Silverado, now mine,
and loaded it up to +7K and towed a +14K utility trailer. Bent the frame
and almost killed me and the two employees I had out on a wind farm.
Didn't know what GCWR was till some where in the 90's when was shopping
for my Suburban.
Here are the stickers for at 1980 Silverado C10. Door and golve box.
It will give you a ball park and note that OEM usually increase the
ratings every few years or so.
This is the weight tag from local dumps on that Silverado. Me and nephew,
both around 180 lbs. AC, Auto, 5.7L, 'heavy half' (Big Ten), over sized
tires and wheels, after market rear bumper, front bumper guard and
about 50 lbs of misc tools and stuff.
So 5,160 lbs - 360 = 4,800 - 50 = 4,750 is the approx weight of the
Silverado with it's options.
I do not, nor have I looked for it's MTWR, yet...
-Ben Picture of my rig
1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...
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345jeep
Fort Worth, TX
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My dad had a 74 Blazer with about the same set up. His transmission was the weak link. Motor and gears were stout.
2010 Skyline Layton 190
2008 Jeep Grand Cherokee Overland 5.7L V8 4x4 3.73 Axles
Me, DW, daughter, Golden Retriever and Goldendoodle
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BlackiceLSC
Sonoma County
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I used to tow with a 76 GMC High Sierra 4x4.
we swapped in a 400 cu.in.
had a TH350 trans
had a 'corporate' rear end.
towing cap was just as stickered above.
I towed an open trailer with 3200 lb race car, bed fully loaded(about 800 lbs of gear) from San Francisco to Las Vegas...that truck didn't even know there was a load on it.
Just be sure you have tires that can handle the load your truck can cover.
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mkirsch
Rochester, NY
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Joined: 04/09/2004
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Both my Dad's '78 and Mom's '79 had door stickers with GAWR and GVWR info.
As a ROUGH rule of thumb, you can tow about 7 times as much as you can carry (a conservative 14% tongue weight) assuming you start with an empty truck.
That's just holding it up off the ground. Now, if you want to go anywhere with it, that's a power issue. How fast do you want to go?
We used to load 3000lbs of cow in the back of Dad's '78 truck (GMC Sierra 25 or 2500 w/7200GVWR and 350 4bbl). We never got anywhere fast like that, but it got the cows to market.
Nowadays, you can hit the Edelbrock catalog and really pump that old 350 up, but stock, you probably don't want to tow much and expect to keep up with traffic.
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